JPH0139001B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of combustion of a carbonaceous pulverized solid fuel such as pulverized coal.

In conventional slugging furnaces, such as for steam generation, pulverized bituminous or semi-bituminous coal is fed into the reaction zone. The combustion temperature is maintained at or above the ash melting temperature to convert most of the non-combustible ash present in the fuel into molten slag. Such conventional furnaces are designed to operate at or near atmospheric pressure and, as a result, are typically very large and require ceramic construction to prevent erosion of the combustion chamber by hot combustion products. It requires the use of the human body, releases large amounts of pollutants into the atmosphere, and has severely limited uses. Such large furnaces have high heat losses, low overall thermal efficiency, and undesirably low power density, ie, thermal power output per unit volume of the furnace.

The present invention provides a method for burning solid or liquid carbonaceous fuels with high efficiency, optimized energy recovery from the fuel, and improved power density. Improved thermal and volumetric efficiency is obtained by providing a mixture of fuel and oxidant gas that spirals through a field of swirling flow, which flows through the slag. This serves to separate the majority of the ash and slag from the gaseous combustion products by centrifugal force without loss of undesirably large unburned portions of the ash and slag. A combustion device implementing the method of combustion of carbonaceous pulverized solid fuel of the present invention occupies less space than a conventional combustion device having a comparable thermal power output. The combustion method of the present invention involves controlling the temperature in the reaction zone to melt most of the non-combustibles present in the fuel, depositing it in liquid form on the walls of the reaction chamber and separating it from the reaction zone. removing and adding chemicals to the reaction zone to reduce pollutants in the exhaust gas. The apparatus implementing the combustion method of the invention is particularly well suited for use with magnetohydrodynamic generators. The apparatus implementing the combustion method of the invention is also suitable as an accessory to thermal energy installations designed and configured to fire natural gas or oil, and for metallurgical processing or cracking, coal pyrolysis, Or it can be used to perform other chemical processes such as production of producer gas or synthesis gas.

The apparatus for carrying out the combustion method of the invention has a chamber with walls forming a reaction zone. This chamber has a fuel inlet through which particles of solid fuel are supplied. For most applications, the fuel particles have a particle size of about 750 microns or less. Suitable fuels include pulverized coal, crushed oil-bearing shale, petroleum residues,
etc. The chamber also includes an oxidant inlet through which a swirling oxidant gas, such as air or pure oxygen, is introduced into the combustion zone. Downstream of the inlet is an outlet through which gaseous reaction products and fine particles of slag not collected on the inner walls of the chamber are discharged from the chamber.

A feature of the device for carrying out the combustion method of the invention is that the particles of fuel are almost completely reacted before they impinge on the inner wall of the chamber. This is achieved by controlling the pneumatic trajectory within the reaction zone so that the combustion time of the fuel particles is shorter than the flight time of the particles to the chamber walls. The main characteristics of combustion in pneumatic trajectory optimize the mixing and also the carbon capture by the slag, the rate of descent, the type or composition of the fuel, the slag removal rate, the carbon combustion efficiency, and the combustion zone additives. This means that it is possible to change the combustion process depending on the combustion conditions. Because of this feature, the combustion method of the present invention allows the device to be significantly smaller than a combustor of comparable thermal power output.
Furthermore, since the present invention controls the flight of the particles undergoing combustion, the apparatus implementing the combustion method of the present invention is particularly well suited for the production of generator gas, synthesis gas, or metallurgical processing as will be described later.

In one embodiment of the invention, the oxidant gas is introduced into the cylindrical chamber in a plurality of separate streams. One gas drop is injected into the reaction zone in a direction substantially parallel to the longitudinal axis of the reaction chamber, and a second stream is introduced tangentially to the walls of the reaction chamber. By regulating the flow rates and speeds of these two gas flows and the fuel introduced into the reaction chamber, in-flight combustion of combustion particles can be achieved and maintained. especially,
In the present invention, a swirling flow of the oxidant and fuel mixture is created in the reaction zone. The swirling flow herein means a substantially pure circular flow or a combined flow of a circular flow and a whirlpool. These two types of flow will be discussed in more detail later, but both types provide a higher level of control over the burning particles compared to that obtained with the spiral flow used in some conventional combustors. It provides a pneumatic trajectory with a fairly long residence time in the reaction zone.

The method of the invention provides for the majority of the slag component of the fuel to be removed from the gaseous reaction products before they leave the reaction chamber. In particular, in the apparatus for carrying out the combustion method of the invention, the reaction chamber is equipped with a slag buffle at the outlet end of the reaction zone. The swirling flow serves to transport the slag particles radially toward the walls of the reaction chamber near the downstream end of the reaction chamber, and the reaction temperature within the reaction zone is maintained at a level that minimizes slag evaporation.
Up to about 95% of the slag is deposited on the reaction chamber walls and is removed as a liquid from the reaction zone. Liquid separation of the slag from the gaseous reaction products is controlled, at least in part, by controlling the relative rates of fuel and air delivery to control the temperature within the reaction zone. As a result, liquid droplets of slag deposited on the interior surfaces of the reaction chamber remain in liquid form and flow to the bottom of the reaction chamber where they are removed via a slag trap or other suitable slag removal and treatment device. Furthermore, the use of a metal water-cooled reaction chamber promotes the expansion of the solidified slag layer on the inner surface of the reaction chamber. Since the layer of solidified slag on the walls of the reaction chamber has a relatively low thermal conductivity, this layer acts as a liner to protect the interior chamber walls and also reduces heat loss. This mechanism for controlling fuel and oxidant delivery is used in conjunction with a slug buttful and a water-cooled reaction chamber to minimize the concentration of evaporated slag in the delivery gas stream;
It constitutes a means for removing most of the slag in liquid form.

In an embodiment of the invention, fuel is supplied to the first reaction zone in the form of finely divided carbonaceous material mixed with and carried by the carrier gas.
The fuel injection device preferably includes a pintle valve device;
This controls the rate of fuel delivery and also distributes the fuel within the reaction zone, as will be discussed in more detail below.
It is desirable to use different fuel distribution patterns within the reaction zone for different modes of operation. This is done by placing the pintle valve in different positions or by varying the injection angle at which the fuel is injected relative to the longitudinal axis of the reaction chamber. In one embodiment, the pintle valve arrangement has a coaxially disposed longitudinally adjustable pintle having a large diameter distal end. This larger diameter distal generally conical surface acts as a deflector and directs the injected fuel radially outwardly from the pintle valve arrangement into a generally conical distribution pattern. Regulation of fuel flow rate is accomplished by a combination of two mechanisms. In the first mechanism, the fuel to carrier gas ratio is varied by increasing or decreasing the carrier gas flow.
The solids-to-gas ratio can be throttled over a wide range, from 100:1 at the top to almost the carrier gas at the front, without using any moving parts in the pintle valve. The second mechanism controls fuel delivery, which is accomplished by longitudinal adjustment of the pintle valve.

The apparatus implementing the combustion method of the invention is specially designed and used in magnetohydrodynamic generators. The apparatus has a second reaction chamber located immediately downstream from the slugging baffle of the first reaction chamber. The apparatus also introduces additional oxidant gas and mixes it with the gaseous reaction products exiting the first reaction zone. With this configuration, the first reaction zone operates in a fuel-rich condition, so that the exhaust gas contains significant amounts of incomplete combustion products, such as carbon monoxide and hydrocarbons. In the second chamber, these products further react to produce additional thermal energy. Since about 90% or more of the slag has been removed in the first reaction zone, the temperature in the second reaction chamber can be raised above the slag evaporation temperature, improving thermodynamic efficiency and increasing thermal power. Can be converted into electrical power.

The apparatus for carrying out the combustion method of the present invention has a reactant delivery device near the inlet end of the second reaction chamber, which allows selected additional reactants to be introduced into the second reaction chamber.
can be added to the hot gas stream entering the reaction chamber. Furthermore, the second reaction chamber has a device for reducing or eliminating the high angular velocity of the gaseous reaction products. In one embodiment, the change in angular velocity is
By injecting supplemental air in a direction and at a rate to balance and offset the angular momentum of this additional oxidant gas with the angular momentum of the reaction products exiting the first reaction zone. It will be done. The introduction of this additional oxidant gas into the second reaction chamber provides a means of eliminating swirling of the gaseous reaction products through momentum exchange.

It has been found that the method of the invention can be advantageously used in the melting of metal ores such as copper, zinc, iron, lead, nickel and silver oxides and sulphides. In a metallurgical process, the fuel delivery rate is first adjusted or predetermined to operate at a level sufficient to maintain the desired temperature conditions within the fuel zone. Once the fuel delivery level is determined, the air delivery is adjusted to provide fuel-rich or fuel-rich or fuel-poor operation within the combustion zone as desired. In many metallurgical processes, it is preferred to maintain the reaction zone on the fuel-rich side of the stoichiometry to provide a reducing atmosphere into which the beneficiary ore is introduced. The metal ore is preferably introduced into the reaction zone either as a pulverized powder, mixed with a pulverized solid fuel, or mixed with a carrier gas, through a separate pintle valve or other suitable reactant injection device. injected into the reaction zone. The beneficent ore thus injected into the fuel-rich stream of gaseous reaction products is reduced by the mixed fuel-rich gas, and the molten metal droplets are transferred to the rotating gaseous reaction products. is formed downstream of the With proper adjustment of the apparatus, the molten metal droplet is subjected to centrifugal force as it progresses toward the discharge end of the reaction zone and is accelerated toward the radial end of the reaction chamber. The swirling flow within the combustion zone thus serves to separate the molten metal from the gaseous combustion products and deposit it on the walls of the reaction chamber, with the deposited metal being removed from the chamber walls. It is carried away with the slag.

In most metallurgical processes, multi-fuel operation is used to maintain a reducing atmosphere within the combustion zone;
Application of the present invention is not limited to this.
As a special example, metallic copper is made from copper sulfides such as chalcopyrite and chalcocite, where the combustion zone is operated in balanced stoichiometry or in a slight oxidant excess, i.e., with multiple oxidants. .

Another feature of the invention is that other reactants are added to the reaction zone, either together with the beneficiary ore or separately, for the purpose of the chemical reaction indicated by the particular type of reaction chemistry that takes place in the reaction zone. for example,
Additives are used to facilitate the separation of slag and metal products or to increase the capture of potentially airborne contaminants generated during the combustion process. By adding selected reactants and controlling temperature, sulfur oxide (SO _x ) effluents can be removed from gaseous combustion products without the use of conventional deposited gas scrubber equipment. To control SO _x emissions, treatment chemicals such as carbonates are added to the feed fuel or introduced separately into the reaction chamber.
The formation of nitrogen oxide ( _NOx ) contaminants is controlled by maintaining fuel-rich combustion conditions, which limits the temperature to a sufficiently low level to prevent rapid formation of _NOx .

The apparatus implementing the combustion method of the present invention can be used to produce generator gas or synthesis gas. This equipment is used to combust a carbonaceous fuel to produce generator gas of the type that is fed to a conventional oil or gas fired burner. It is desirable that such a generating furnace gas contain as much carbon monoxide as possible. This increases the calorific content of the gas and increases its economic value. Although some water is carried into the reaction zone with the coal and air, it is undesirable to add water or steam to the reaction zone. This is because it reduces the amount of carbon monoxide produced. However, it is desirable to inject a suitable chemical into the reaction zone to remove SO _x . When oil and gas are in short supply, devices implementing the combustion method of the present invention can be used to produce clean burning fuels to replace oil and natural gas.

Synthesis gas is produced by substituting pure oxygen for air during the combustion process and injecting an appropriate amount of water vapor to achieve the desired ratio of carbon monoxide and hydrogen in the synthesis gas. The reason for using oxygen instead of air is to remove nitrogen, which is a diluent in the syngas and is often a harmful component. Since coal can be burned cleanly and SO _x and slag can be removed from the exhaust gas in an apparatus implementing the combustion method of the present invention, synthesis gas can be produced at a lower cost than with conventional techniques.

Another feature of the invention is that the apparatus implementing the combustion method of the invention can be used to generate hot exhaust gases for use in processing carbonaceous materials such as coal or shale. An apparatus suitable for the treatment of such carbonaceous materials comprises a first stage comprising an apparatus for carrying out the combustion method of the invention and one or more stages connected to the apparatus for carrying out the combustion method of the invention. has. Carbonaceous material is fed to one or more of these downstream stages, and exhaust gas flowing from the first or second stage to the subsequent stage provides heat for processing the carbonaceous material. The solids are separated from the gaseous components emerging from the final stage of the device and volatile hydrocarbons are recovered. In coal processing, hot gas evaporates the water and hydrocarbons in the coal. The valuable hydrocarbons are recovered and the lighter weight residual coal is transported more economically than raw coal. For example, coal contains up to 20 percent water by weight. The cost of transporting coal containing such a large amount of water is high enough to more than offset the cost of processing the coal using equipment implementing the combustion method of the present invention. When shale is retorted by heat treatment, the kerogen in the shale decomposes into oil, which is then evaporated and separated from the solid shale mineral. The oil is treated by flash cracking. That is,
A stream of oil is injected into the downstream stage of the device and rapidly heated. This oil cracks to light hydrocarbons which are then separated from the inert gaseous combustion products.

The invention will be better understood and other advantages will emerge from the detailed description of embodiments of the invention which follows with reference to the drawings.

Next, the general configuration of the present invention will be explained.

In order to understand the basic concept of the present invention, FIG. 1 briefly shows a combustion apparatus 10 for carrying out the method of combustion of carbonaceous pulverized solid fuel of the present invention. This device 10 has a reaction chamber or combustion chamber 21.
1 is a metal cylinder symmetrical with respect to the longitudinal axis Z, forming a cylindrical reaction or combustion zone 22 . At the inlet end 23, primary or longitudinal air enters the reaction zone 22 along a line parallel to said axis. Downstream from the inlet end 23 is an injection duct 24 adapted to introduce secondary air tangentially into the reaction zone 22 . A fuel injection pintle valve 25 is installed coaxially with the chamber 21 at the center of the inlet end 23, and this pintle valve 2
5 has a pintle 27 for adjusting the length within the fuel inlet pipe 29, and the fuel is supplied to the inlet pipe 29.
9 into the reaction chamber. pintle 27
has a tapered end 31 to direct the fuel radially outwardly from the longitudinal axis into a bell-shaped dispersion envelope 4.
It is designed to divert the direction towards 1. When the pintle is moved to the left as shown in Figure 1,
Valve seat 3 with the tapered surface of end 31 at the end of tube 29
3 and gradually reduce the flow rate of fuel entering the reaction zone 22. With this configuration, the pintle valve 25 variably controls the flow rate of the supplied fuel. At the right-hand end, the reaction chamber 21 has a baffle 35 with a central opening 37 through which the gaseous reaction products generated in the reaction zone 22 exit the chamber. The baffle 35 separates fines and slag droplets from the gaseous reaction products. Therefore, the opening 37
The flow exiting through the liquid slag does not contain significant amounts of solid particles.

As shown in FIGS. 2a-2c, the primary air flowing annularly around the pintle valve 25 into the reaction zone 22 is intercepted by secondary air entering the reaction zone from the duct 24. A carbonaceous pulverized solid fuel, for example pulverized coal, is delivered to the reaction chamber 21 in the form of a dense mixture with a carrier gas such as nitrogen ( _N2 ), compressed air or a gaseous fuel. The tangentially injected secondary air stream 47 thoroughly mixes with the fuel and primary air and accelerates the solid fuel particles according to fluid principles that will be explained in more detail below. As shown in Figure 2d, the mixture of burning fuel particles and hot gaseous reaction products travels along a helical path 4.
9 at the downstream end of the reaction zone 22 and exits the chamber 21 through the central opening 37 . As the reaction products are pushed inwardly by the baffle 35, the angular velocity increases rapidly in the region close to the baffle, and the slag droplets are separated from the gas stream by centrifugal force and are mostly deposited on the walls of said chamber and in the buttful. It is deposited on the inner surface of 35.

Particles carried within the bell-shaped dispersion envelope 41 move lengthwise within the chamber at an average velocity determined by the combined air and fuel flow rates. Small particles are caught in and carried along with the flow of the mixture, while large particles move along trajectories determined in part by their original velocity vectors. Large particles are accelerated by the rapidly rotating gas, but this acceleration is less than for small particles.
That is, as shown in FIG. 1, line 43 indicates the outer limit of the helical trajectory of relatively large fuel particles, such as particles having a particle size of about 100 microns. Such large particles actually spiral around the longitudinal axis within envelope 41 rather than along line 43, of which line 43 marks the outer limit. Similarly,
Relatively small particles, e.g. coal particles of about 10 microns in size, follow a helical path within envelope 41, line 45 marking its inner limit. Thus, substantially all particles ranging in size from about 10 microns to about 100 microns travel along helical trajectories within envelope 41 between lines 43 and 45. The mixing of the fuel and the two air streams results in an exchange of momentum and a flow of mixture that extends in a generally cylindrical spiral along the length of the chamber. For reasons that will become more apparent later, it is desirable to maintain a field of swirling flow or a combined field of swirling/eddy flow within the main portion of reaction zone 22.

The bell-shaped dispersion envelope 41 shown in FIG.
15.2 meters (approximately 50 feet), assuming a flow rate of the injected carrier gas and fuel mixture of approximately 3.05 to 15.2 meters (approximately 10 to 50 feet) per second. However, the invention is not limited to the above flow rate values or to the ratios of these flow rate values. By selecting the optimal relationship among the secondary air flow rate, primary air flow rate, fuel inlet flow rate, and fuel direction, the shape of the envelope 41 can be adjusted over a wide range. This selection is made according to the fuel used and the characteristics desired for the process at hand.

In some cases, operation in a fuel-rich environment or reducing atmosphere is desirable. For example, fuel operation is desirable to reduce reaction temperatures and limit slag evaporation, as discussed below.

Next, we will consider the design of the reaction chamber.

In order to make the reactor compact, it is necessary that the fuel particles be small. Generally, the fuel particles should be about 750 microns or less in size, preferably about 75 microns or less in size. These small particles burn within a few milliseconds. In a reactor carrying out the combustion method of the present invention, sufficient centrifugal force is generated by the swirling gas to move the particles toward the inner wall of the reaction chamber, but almost all of the particles are completely removed before colliding with the chamber wall. It is designed to burn.
For example, particles with a particle size of 75 microns burn within about 60 milliseconds. Preferably, the pneumatic trajectory through which the particles are injected is controlled such that the force acting on the particles is such that the particles are completely combusted before reaching the chamber walls.

It is generally understood that the effects of aerodynamic drag on small particles are much greater than on large particles. For example, when a small particle enters a swirling gas in a reaction zone, the oxidant gas propelled by the particle creates a drag force that almost simultaneously changes the velocity and direction of the small particle. This corresponds to the speed and direction of the swirling gas. In contrast, a very large particle, due to its inertia, tends to continue moving at the speed and direction it had when it entered the swirling gas. For the small particles that are the subject of this invention, almost all of the particles are at the velocity of the swirling gas within a few milliseconds after they enter the reaction zone.

As these particles swirl in the gas, they create a centrifugal force that is directly proportional to the mass of the particle and the angular velocity of the particle. Large particles have a greater centrifugal force acting on them and are less affected by drag than small particles. Therefore, larger particles move towards the outer wall faster than smaller particles. By controlling the tangential velocity of the swirling gas, the centrifugal and drag forces acting on the particles can be controlled. From this, by suitably selecting the tangential velocity of the swirling gas, large particles can be burnt out before they impact the walls of the reaction chamber. The interaction of the incoming gases creates a transport effect that can change the centrifugal and drag forces acting on the particles. By controlling the ratio of the tangential and longitudinal gas flow rates, nearly all of the particles can be burned off before they impact the reaction chamber walls. Furthermore, the greater the degree of swirl of the gas flow within the reaction zone, the longer the flight time of the particles within the reaction chamber.

In the design of the reaction chamber, it is desirable to maximize the amount of slag that can be trapped within the chamber. Since small particles do not move toward the reaction chamber walls as quickly as large particles, very small particles usually escape through the chamber opening and there is some loss of fine slag droplets. However, the length of the reaction chamber and the size of the opening should be at least about 90 to 95% of the slag.
be captured indoors.

Care must be taken to ensure that the injection rate of the fuel particles is so high that the particles do not reach the reaction chamber walls due to their momentum before they are combusted.
In other words, the velocity of the fuel particles is made sufficiently lower than the velocity of the swirling gas so that the gas acts on the incoming particles and traps them in the swirl for a sufficient amount of time to completely eliminate them. It is necessary to allow it to burn.

Next, the behavior of particles within the reaction zone will be explained.

In order to fully understand the characteristics of the swirling flow used in the present invention, a detailed discussion of the gas flow and the forces exerted by this gas on particles is provided.

There are two types of gas flow within the swirling gas within the reaction zone: eddy flow and swirl flow. In theoretically pure eddy flow, tangential velocity decreases as a function of radial position. In other words, the maximum tangential velocity is near the center of the rotating flow field. Eddy flow is characterized mathematically by the following equation.

V _t ~R _p V _p /R where, V _t = tangential velocity, R _p = radius of the reaction chamber, R = position on the radius, and V _p = tangential velocity at the outer end of the radius.

A theoretically pure eddy flow is graphically illustrated in FIG. In FIG. 3, curve 51 is a plot of tangential velocity as a function of radial distance from the axis of rotation in an eddy flow field. As shown by curve 51, the tangential velocity increases exponentially with decreasing radial position and is extremely high near the axis if pure eddy flow is maintained.

In swirling flow, the entire fluid rotates together like a solid body. This type of flow is called “pure swirling flow”
I will call it. Pure swirling flow is characterized mathematically by the following equation.

V _t ~Rω where V _t = tangential velocity, R = radial position, ω = angular velocity at R.

That is, in a swirling flow, the tangential velocity of the gas at any radial position R is directly proportional to this radial position from the axis of rotation. This is, of course, a property of rotating solid bodies whose constituent parts are in a constant relationship to each other. The angular velocity ω is the same at all radial positions. Therefore, in pure swirling flow, ω is constant for all points (positions) in the same cross section, and the maximum tangential velocity is Unlike, it occurs at the outer radius end. Figure 4 shows pure swirling flow. In FIG. 4, line 53 represents the tangential velocity plotted as a function of radial distance from the axis of rotation Z.

In mixing the axial air with the tangential air, the gas flow within the reaction zone 22 is controlled so that the gas flow approximately corresponds to the velocity profile shown by curve 55 in FIG. This curve is a typical flow pattern in reaction zone 22. Curved portion 56
indicates a region where the velocity increases as an approximately linear function of radial distance from the axis of rotation, corresponding to a purely swirling flow. A curved portion 57 indicates a portion of the flow field that approximately corresponds to a pure eddy flow. In the field of this combination of swirling and whirlpool flow, the tangential velocity near the axis increases almost linearly with the distance from the axis, reaching a maximum velocity at a distance approximately equal to the radius of the buff-full opening 37. Beyond this point outwardly, the velocity varies approximately inversely with distance from the axis, corresponding approximately to that of the eddy flow described above and shown in FIG. Therefore, the flow field used here approximates a pure swirling flow in the core region of the combustion zone, with a transient section indicated by a in FIGS. 3 and 4, and in the outer shell portion of the flow field. substantially similar to whirlpools.

The flight time of large particles can be greatly increased by minimizing the tangential velocity of the gas that encounters the particles early in their flight through the reaction chamber. Therefore, it is desirable to make the diameter of the heart region from R=O to R=a as large as practicable. The actual diameter of the core region of the swirling flow varies along the length of the reaction chamber, and near the downstream end there is a
It is almost equal to the radius of 7. In the upstream part of the combustion zone, the radius "a" of the core region of the swirling flow can be maximized by controlling the speed, flow rate, and fuel injection mode, thereby favoring slag capture. The central area can be made as large as possible to achieve a good result.

According to the present invention, by controlling the velocity and flow rate of the fuel and the two inlet air streams, the momentum transfer between the axial and tangential air streams and the fuel is controlled so that the flow within the reaction zone 22 is controlled. The field is made similar to the swirling/eddying flow shown in FIG. 5, and therefore a long flight time of particles is realized. The diameter of the reaction chamber is approximately
By making it as small as 45.7 centimeters (18 inches), a flight time of about 30 to 70 milliseconds can be obtained for large particles. This pneumatic trajectory control of chemical reactions in free flight minimizes the loss of unburned fuel in the slag,
The amount of slag escaping from the reaction chamber through opening 37 can be limited. This effect can also be enhanced by making the velocity of the injected fuel less than the velocity of the inlet tangential flow of oxidant gas and by allowing the fuel to block the portion of the oxidant gas flow that attempts to increase its angular velocity. .

A notable difference between the two streams described above is the residence time of the particles in the reaction zone 22. For similar particles injected at the same radius into these two types of flows, their residence time is much longer in the swirling flow than in the eddy flow. Therefore, in order to increase the flight time, it is preferable to operate under conditions that generate a swirling flow within the reaction zone 22. This is a very important feature of the invention, which allows for increased power density. For example, a conventional Lurgi gasifier has a power density of about 4.54 kilograms (10 pounds) of coal per hour of about 0.0283 cubic meters (1 cubic foot) of reaction chamber when operated at 20 atmospheres. . In contrast, equipment implementing the combustion method of the present invention has a power density of about 345 kilograms (760 pounds) of coal per hour of reaction chamber when operated at the same pressures described above.

The advantage of maintaining a predominant swirling flow within a device implementing the combustion method of the invention can be best understood by considering the hydrodynamics of particles carried within the swirling gas. To reiterate, the object of the present invention is to retain large particles for a sufficiently long flight time so that they can react almost completely and form slag droplets before they impact the walls of the reaction chamber. It is to decompose it into. The apparatus implementing the combustion method of the invention and its operation minimizes the radial acceleration of unburned and partially burned particles, while
The design is such that most of the slag droplets reach the reaction chamber walls. The means for achieving this can be best understood by considering particles in the reaction zone.

Now consider a particle entering the reaction zone. Initially, only drag acts on this particle.
Considering a spherical particle, this drag force (F _d ) is as follows.

F _d = C _d P _g D _p ² (V _g −V _p ) ² /2g where, C _d is drag density, P _g is gas density, D _p is particle diameter, V _g is gas velocity, V _p is the velocity of the particle and g is the acceleration of gravity.

However, because small particles are lighter in weight, or have less mass, they are more affected by the drag forces exerted on them by the swirling gas than larger, heavier particles. Since all the particles that are the object of the present invention are relatively small, the drag forces acting on most of these particles bring them almost immediately to a velocity equal to that of the swirling gas.

When a particle rotates, a centrifugal force (F _c ) acts on the particle. According to the laws of physics, this centrifugal force is as follows.

F _c = MRω ² where M is the particle mass, R is the radial position of the particle, and ω is the angular velocity of the particle.

From this equation, the greater the mass of a particle, the greater the centrifugal force that forces it toward the inner wall of the reaction chamber. The velocity imparted to the particles is controlled by controlling the angular velocity so that the centrifugal force is not too great, so that the particles do not reach the reaction chamber walls before they are completely burned. In the spiral flow, the velocity is high near the center of the reaction chamber, and fuel particles injected into this rotating flow are initially subjected to a large centrifugal force and rapidly accelerated in the radial direction. On the other hand, in a swirling flow, under the same injection conditions, the same particles will experience a relatively small centrifugal force and therefore initially experience a low radial acceleration. Drag forces mainly control the movement of very small particles, so once these particles are spun around, they tend to stay in the same position in the gas and only move slowly toward the reaction chamber walls. .

The tangential acceleration (dVθ/dt) of the particle is given by the following equation.

dVθ/dt=18μ/P _p D _p ² d(V _g −V _p )/dt As can be seen from this equation, the acceleration of a particle is inversely proportional to the square of the particle diameter. Therefore, small particles are
The velocity of the swirling gas is faster than that of the large particles, and the surrounding gas is constantly sliding into contact with new oxidizing gas as the large particles move into different gas environments as they fly. Do not attempt to move relative to the gas. This prevents the development of a blanket of reaction products around the large particles and significantly increases the combustion of the large particles. The extent to which these benefits can be realized depends, in part, on the degree to which the flow field approximates pure swirling flow.

Figure 6 shows the behavior of particles of a given size in three different flow fields. The radial position of 75 micron particles in a chamber with a nominal diameter of approximately 11/2 feet was investigated under three different conditions. Curve A is
This shows that in a pure eddy flow, particles reach the chamber wall in about 10 milliseconds. Curve B shows that in a combined swirling/eddying field, this particle reaches the chamber wall in about 30 milliseconds. Curve C shows that in a purely swirling flow it takes more than 70 milliseconds for the particles to reach the chamber wall. The burning time of this particle is
Since it is longer than 10 milliseconds, pure eddy flow cannot achieve the intent of the present invention. As the flow field more closely approximates a pure swirling flow, even larger particles can be combusted in a chamber of this size. Having a larger chamber allows flying combustion of particles within the eddy stream, but this is economically disadvantageous and also reduces power density and efficiency.

The volumetric or flying combustion obtained as described above provides very high thermal efficiencies and avoids combustion on the walls, the associated loss of carbon in the slag, and excessive loss of heat to the walls. Additionally, on-wall combustion requires transporting the oxidant to this wall, thus requiring the use of extra air and preventing maintenance of a reducing atmosphere in the outer regions of reaction zone 22. Additionally, extremely high power densities can be obtained by providing longer residence times for a given chamber diameter and increasing the flight "scrubbing" of larger particles.
Because the apparatus for carrying out the combustion method of the present invention minimizes the relative velocity between the rotating gas and the large particles, the combustion of large particles is increased and the reaction zone 22 is free from excess unburned particles. Can operate in fuel-rich conditions without wall deposits. The ability to operate fuel-rich facilitates maintaining the reaction zone operating temperature at a temperature that does not result in excessive evaporation of the slag. Therefore, in an apparatus implementing the combustion method of the present invention, more than 90% of the slag component of the injected fuel can be removed as a liquid before the gaseous reaction products leave the reaction chamber.

Figures 7 and 8 show an apparatus for carrying out the combustion method of the invention, which is well suited for the combustion of pulverized coal to generate a hot plasma stream for driving a magnetohydrodynamic generator. In addition to the components described above with respect to FIG. 1, the apparatus includes an oxidizer manifold 61 through which air from a source 65 flows through secondary air duct 24 to inlet 59. , flows tangentially into the reaction zone 22.

As shown in detail in FIG. 8, a pintle valve 25 centrally located at one end of the device receives fuel from a fuel source 63, which passes through an inlet tube 29 and is deflected radially from the pintle end 31. I am made to do so. The longitudinal adjustment of the pintle is achieved by means of an externally threaded pintle sleeve 28, which
8 is rotatably supported in the internally threaded hole.

13 and 1.
A separate fuel mixing and dense phase transport system is shown in FIG. 4 and described in detail below. The primary function of the fuel source 63 is to supply pulverized coal onto the carrier fluid, and the ratio of coal to fluid volume may be between 0:1 and 0:1.
It can be adjusted over a range of 100:1. The flow of pulverized coal placed on the carrier fluid and mixed therewith, that is, the entrained flow, has flow characteristics similar to those of a viscous fluid, and when this entrained flow is dispersed through the pintle valve 25, it is pulverized. The coal is valve 25
1, as shown by the bell-shaped dispersion envelope 41 in FIG.

7 and 8, hot compressed air from an oxidizer source 65 is supplied through a manifold 61 to provide first, second and third air streams to the apparatus. The manifold 61 is a combustion chamber, that is, a reaction chamber 2.
a main duct 66 extending from the oxidant source 65 substantially parallel to the longitudinal axis of the chamber 21 and a first branch duct 67 extending perpendicularly towards the chamber 21 , the high pressure primary air of the duct 67 being transferred to a gas reservoir 69 . From the gas reservoir 69, the primary air passes through a multi-opening flow straightener 70. This primary air enters the reaction zone 22 in a direction substantially parallel to the longitudinal axis of the chamber 21 and passes through an annular space surrounding the pintle valve 25 .
In the gas reservoir 69, the volumetric expansion causes the air to reduce its velocity and be directed by the walls of the gas reservoir toward and past the flow straightening device 70. 8th
As shown in detail in the Figures and FIG. 9, the device 70 is a freely assembled assembly of silicon carbide wings that fit together to form a multi-aperture assembly such that the primary air flow is Pass this. Alternatively, the wings may be made of Inconel 800 or other corrosion resistant high temperature alloys, and the overall design may be an all-metal construction. In this case, the blades can be water-cooled using conventional cooling methods.

The secondary air is supplied from the oxidizer source 65 through the main air duct and the branch duct 24 to the tangentially aligned air inlet 59 at a sufficient velocity;
A rotating mixture of fuel particles, primary air and secondary air is created within the reaction zone 22. In order to maintain swirling flow within the reaction zone and regulate the reaction temperature, it is desirable to control the relative flow values of primary and secondary air and the flow rate of air relative to the incoming fuel. To provide such parameter regulation, conventional fluid valves (not shown) are installed in air ducts 67 and 2.
4 can be used to preselect or continuously regulate the respective flow rates. In one example, ceramic (Zerconia) bench lily devices are inserted into the ducts 24 and 67 to restrict the flow rates and preset the total amount and ratio of the two flow rates.

Controlling slugging so that substantially all of the slag component of the fuel is deposited on the walls of the combustion chamber is a feature of considerable importance. Optimum separation of the slag from the gaseous reaction products begins in the reaction zone 22.
This is done by creating and controlling a swirling flow within the reactor and then regulating the reaction temperature to minimize evaporation of the slag. Temperature control is achieved by regulating the temperature of the inlet air stream and selectively varying the air-to-fuel ratio to maintain a fuel-rich mixture within the reaction zone. Due to the multi-fuel combustion, a significant portion of the carbon contained in the coal leaves the reaction zone 22 as carbon monoxide, limiting the generation of thermal energy within the reaction zone and controlling the operating temperature within the reaction chamber 21. be done. By controlling the temperature along with the centrifugal propulsion that moves the slag particles towards the walls of the chamber 21, the gaseous reaction products are removed before they escape from the reaction zone through the central opening 37 of the buffer 35. More than 90% of slag can be removed from the flow.

Even if the inner surface 71 of the combustion chamber is coated with a refractory ceramic material, slag, high-velocity flow,
The refractory material is likely to be peeled off from the wall of the chamber 21 due to the erosive action of the burning fuel particles, and when the refractory material is peeled off, the metal inner surface 71 of the chamber begins to erode. The present invention avoids this drawback by forming a protective layer of deposited and hardened slag on surface 71 to limit further erosion. For this purpose, metallic coolant conduits 73 are provided on the inner surface 71 of the chamber 21. Conduit 78 forms a water-cooled lining for reaction chamber 21 to retain and solidify sufficient slag to form a protective slag layer with relatively low thermal conductivity. Conduit 78 is supplied with coolant by conventional mechanisms, namely manifolds 74 and 7.
5 is used.

As shown in detail in FIGS. 7, 8 and 10, the buttful 35 is an annular plate disposed on its surface and extending approximately perpendicularly to the longitudinal axis at the downstream end of the chamber 21. It has a double coil of coolant conduit 77 arranged. One of the functions of Batsuful 35 is
Preventing slag droplets that have not yet reached the walls of chamber 21;
The aim is to minimize the slag and ash components of the gaseous products escaping from this chamber. Furthermore, upon reaching the downstream end of the reaction chamber, the rotating flow of gaseous reaction products is forced radially inwardly toward opening 37 by buffle 35 . As the rapidly rotating gas stream is forced inward, the angular velocity increases by a factor of three, four or more. This sudden increase in centrifugal force causes substantially all of the slag component of the fuel to be thrown out of the gaseous reaction products and deposited as a layer of liquid slag on the internal surface 71 and baffle 35 of the combustion chamber.

This liquid slag flows by gravity toward the bottom of the reaction chamber, passes through slugging port 78, and exits at slug trap port 79 at the bottom of the chamber. As shown in detail in FIGS. 8 and 10, the slugging port 7
A short section of the cylindrical conduit forming 8 is cooled by cooling water flowing through a conventional water jacket having an inlet 80 and an outlet 81. In the area of the slugging port 78, the coolant conduit 73 is connected to the adjacent conduit 7 at the location of the slugging port 78.
3 to create a shaped inner surface portion 82 forming a substantially opening between the two. The slag dumping device preferably has a pressurized slag sump (not shown) to prevent gaseous reaction products from escaping through the slugging port.

In magnetohydrodynamic applications, the apparatus for carrying out the combustion method of the invention further comprises a secondary reaction chamber 85 connected to the downstream end of chamber 21 and forming a second reaction zone 88. is formed. Secondary reaction chamber 85 receives gaseous reaction products from chamber 21;
This hot gaseous reaction product is transformed to create, at its outlet 87, a high-velocity plasma suitable for injection into the plasma channel of a magnetohydrodynamic (MHD) power plant. This MHD device is conventionally well known, and its explanation will be omitted in this specification.

Gaseous reaction products exiting reaction zone 22 enter second reaction zone 88 through opening 37 . Immediately downstream of the baffle 35 is a reactant injector 90 adapted to inject a selected chemical reactant, such as potassium carbonate, into the hot gas stream. The injection device 90 includes a reactant feed pipe 91
, which inlet tube extends transversely to the axis of chamber 85 and is supported coaxially with coolant conduit 92 .
A reactant injector having a sleeve 94 is attached to the reactant inlet pipe 91 substantially on the axis of the chamber 85, and the sleeve 94 coaxially supports a pintle 95 therein. The coaxial pintle reactant injector is preferably a compact version of the coaxial pintle valve 25 previously described and shown in FIGS. 1 and 8. For efficient performance of a magnetohydrodynamic generator, it is desirable that the gas passing through the magnetohydrodynamic channel have electrical properties that correspond to those of a highly conductive fluid. Therefore, in magnetohydrodynamic applications of the present invention, it is preferred that the gas stream exiting outlet 87 of reaction zone 88 be substantially completely and uniformly ionized. The injection of potassium carbonate completely and uniformly ionizes the reaction products as they pass through reaction zone 88 . In another application of the apparatus for carrying out the combustion method of the present invention, a reactant injection device 90 is used to add something to the swirling gas stream immediately after it enters the reaction zone 88 through the opening 37. Additional or chemical reactants can be injected.

Immediately downstream of reactant injection device 90, a second
That is, the secondary reaction chamber 85 is equipped with a device for injecting the amount of preheated air necessary for a complete stoichiometric reaction. This third air is injected with sufficient tangential velocity to eliminate the angular velocity of the gaseous reaction products received from opening 37 by momentum exchange. More specifically, this second stage de-swirler includes a tangentially extending air duct 96 that receives hot air from manifold 61 and distributes it to a toroidal air distributor. Send it to 97. This air distributor 97
8 and 12, extends around the periphery of the second or secondary reaction chamber 85, into which a high-velocity tangential air flow is directed from the distributor 97. There are twelve air inlets 98 for introduction into the reaction zone 88. When a device implementing the combustion method of the invention is used as a plasma source for a magnetohydrodynamic power device, it is desirable that the output plasma stream has substantially no angular velocity. For this purpose, a duct 96 and a distributor 9
The airflow through chamber 85 is regulated to reduce the angular velocity of the gas flow within chamber 85 to zero. For other applications where angular velocity is not an issue, the volume of air supplied through duct 96 may be controlled to preselect or continuously vary the stoichiometry with reaction zone 88. If desired, the air manifold 61 and some ducts extending therefrom are provided with external water cooling jackets. A conventional manifold is used to supply coolant to this water jacket.

Next, dense phase fuel transport will be explained.

A pulverized fuel, such as coal, is transported from a ball mill or storage facility to the reaction chamber 21 as a dense mixture with a carrier gas through a tubular conduit. Since reaction chamber 21 operates at a pressure of 2 to 8 atmospheres or more, the fuel delivery system is preferably pressurized to approximately the same extent. FIGS. 13 and 14 show a pressurized dense phase fuel transport system used in carrying out the combustion method of the present invention. As shown in FIG. 13, coal hopper 145 is typically fed from a coal storage facility (not shown) through a loading hatch 146 at the top of dome section 147.
It is filled with powdered coal that has been pulverized to the size of a mesh. The pressurized coal hopper may be filled by an intermediate pressurized transport container (not shown) or by e.g.
It is carried out by a conventional screw pump for handling pulverized coal. In addition to the dome section 147, the coal hopper has an intermediate cylindrical section and a lower conical section 148 with an included angle of 30 DEG. A coal fluidization injector 149 is provided at the bottom of the conical part 148,
From this injector, pulverized coal flows through a throttle valve 150 to an ejector device 156. Ejector device 156
accelerates the coal particles to a velocity of approximately 20 feet per second and transports the coal in a dense mixture with air or other suitable carrier gas through coal feed line 158. Reaction chamber 2
1 (Figures 7 and 8). Coal feed line 158 is connected to ejector device 156
It extends from the pintle valve 25 and is connected to the inlet pipe or inlet pipe 29 of the pintle valve 25 . Carrier gas for pressurizing the coal hopper 145 is passed from a gas source 152 through line 153 and through a control valve 154 to an inlet connection at the top of the hopper. Carrier gas is also routed from gas source 152 to fluidizing injector 149 by line 155 and control valve 157. Compressed gas for operating the ejector device 156 is passed from a gas source 159 through a control valve 160 to the ejector inlet. The fluidizing injector 149 and ejector arrangement are shown in detail in FIG. This first
FIG. 4 is a sectional view along the cylinder axis of the fluidizing injector.

As shown in FIG. 14, the fluidizing injector 149 includes a generally cylindrical metal member 166 having a conical portion 167 and a planar flange 170 at its upper end.
has. The flange 170 is the conical part 1 of the coal hopper.
Connected and sealed to the bottom end of 48. Member 16
6 has a 1/2 inch diameter central hole 172 extending vertically and opening into a conical opening 174 with a 45° included angle between opposing walls. The diameter at the top is about 15 centimeters (about 6 inches). A gas manifold 176 is provided between the ends of the conical opening 174 and extends circumferentially around the member 166. A gas manifold 176 is secured to the surface of member 166 overlying a peripheral groove 178 into which gas is distributed from the manifold. Groove 17
8 , a plurality of equally angularly spaced holes 179 extend radially inwardly through the wall of member 66 to central hole 174 . Pressurized carrier gas from gas source 152 is routed through control valve 157 to manifold 176 from where it is distributed to 16 radial holes 179.
through the conical opening 174. This injection of carrier gas causes the pulverized coal within opening 174 to flow and propels the mixture of carrier gas and pulverized fuel downward through central hole 172 . From the base of the member 166, the fluid mixture flows through the throttle valve 150 and into the vertically extending bore 181 of the ejector device 156. fuel throttle valve 150
is, for example, an ordinary ball valve, and its control shaft is connected to be rotated by a gear motor 183. Conventional circuitry is used to monitor and control the gear motor shaft position and regulate the fuel flow through the throttle valve 150 according to the desired volume or amount ratio of fuel to carrier gas.

The ejector device 156 includes a housing 185 having a cylindrical hole 186 extending horizontally therethrough and a vertically extending hole 181 communicating with the horizontal hole through which the pressurized coal is squeezed. Flows from valve 150. A tapered nozzle 187 is mounted within horizontal hole 186 by screw 188 and injects high pressure carrier gas into housing 185. Within housing 185, the gas jet impinges on the downward flow of fine coal and accelerates it outwardly through connector 189 and coal feed line 158. The inner end of the connector 189 is provided with a conical bore 190 which directs the mixture of pulverized fuel and carrier gas to the feed line 1.
Pour into 58. The tapered nozzle 187 is connected to the control valve 16
0 (FIG. 13) to a gas source 159 from which compressed carrier gas is supplied.

In operation, the fluidizing injector 149 creates a region of high-velocity turbulence within the conical opening 174 in which the pulverized coal is mechanically energized and lubricated so that the coal and carrier gas flow smoothly and reliably. Center hole 17
Pass through 2 downward. The internal supply of carrier gas balances the overhead pressure of the pressurized coal hopper 145 and maintains the hopper pressure even as the amount of coal contained within the hopper 145 tapers off. In a preferred method of operation, the fluidizing injector provides a fluidizing volumetric flow rate equal to the sum of the coal volumetric flow rate and the carrier gas losses that occur under steady-state operating conditions.

Once there is a steady state flow of coal flowing downward through the throttle valve 150, the flowing coal is diluted and accelerated by compressed carrier gas injected through a tapered nozzle 187 in the ejector arrangement.
The tapered internal bore of the nozzle 187 provides a focused gas jet, and with appropriately adjusted gas velocity and coal flow rate, the coal particles are accelerated to a velocity of about 20 feet per second, at which speed Continuously flows into reaction chamber 21 through feed line 158 .

Solid fuels are typically micronized to a fineness on the order of 200 mesh, but any suitable range of particle sizes may be used. High solids to gas ratios, such as about 100:1, are easily obtained in the present invention. Approximately 0.7
to 5.6 Kgw/cm ³ (10 to 80 bw/in ² ) to obtain a ratio of around 50:1 at fluidizing (N ₂ ) pressures ranging from 10 to 80 bw/in 2 .
After the coal powder, which has been able to maintain a fairly uniform flow rate, is fluidized and injected through the fluidizing injector 149 for several minutes, the carrier gas supply to the fluidizing injector is cut off. Dense phase coal transport then continues by simply maintaining pressurization of the coal hopper 145 and supply of compressed gas to the ejector device 156. The solids-to-gas ratio and the transport rate in the feed line 158 can be controlled continuously or preselected arbitrarily within the above ranges by controlling the coal throttle valve 150 and the gas supply control valve 160. Set to value.
Conventional circuitry including flow transducers is used to monitor these operating parameters and provide feedback signals to energize control gear motor 183 and control valve 150.
and regulating the speed and pressure of the control air supply.

Dry nitrogen or air is typically used as the fluidizing carrier gas, but nearly any liquid or gas can be used, including petroleum liquids and hydrocarbon gases.

In operation of an apparatus implementing the combustion method of the present invention as a power source for driving a magnetohydrodynamic generator, coal pulverized to about 100 to 200 meshes is placed in a stream of air at about ambient temperature. For applications requiring minimal enthalpy losses, such as plasma generation, the ratio of solid fuel particles to ambient air carrier is in the range of 30:1 to 100:1. This dense phase fuel transport limits the amount of relatively cold air introduced into the combustion zone 22, helping to maximize the temperature level of the output plasma. The coal particle loaded stream is directed through the pintle valve 25 and directed radially outward into the combustion or reaction zone 22 in a bell-shaped dispersion pattern or envelope 41 (FIG. 1). .

The oxidizing agent used to generate plasma is typically around 1590℃
(approximately 2,900〓). This preheated air may be "supplemented" if required by the nature of the coal fuel then used, before being introduced into the combustion zone.
Add oxygen to this air. A helical swirling flow of preheated air is created in the combustion zone 22, into which a flow of carrier gas loaded with coal is directed. To keep the combustion temperature below the slag vaporization temperature, combustion zone 2
Preferably, 2 is operated fuel-rich within a range of about 0.4 to 0.9 of the stoichiometric amount of oxidizer. Thereby, the temperature in the combustion zone 22 is approximately 1650°C to 2090°C (3000° to 3800°C) depending on the composition of the slag.
〓). The hot gaseous combustion products are passed from the combustion zone 22 through the central opening 37 of the baffle 35 to approximately
It escapes at a temperature of 1870℃ (approximately 3400〓). These gases emanating from the fuel-rich atmosphere within combustion zone 22 include slag droplets less than about 10 microns in size and some vaporized slag.

As previously mentioned, the necessary oxidizing agent to stoichiometrically and completely burn the gaseous combustion products is added to the second chamber 85 through an inlet or air duct 96 and a distributor 97. to be introduced. Due to the complete combustion of CO and _H2 in the reaction zone 88, the temperature of the gas stream at the outlet 87 is approximately 1870 °C.
(approximately 3400〓) to approximately 2810℃ (approximately 5100〓). The outlet 87 is directly connected to a magnetohydrodynamic generator or other device for the utilization of thermal and/or gas kinetic energy. There are very few slag droplets, ash, and unburned fuel particles that are not collected on the walls of chamber 21. Therefore, they often gasify when exposed to high temperature conditions within reaction zone 88.

In the apparatus for carrying out the combustion method of the invention, the pintle valve 25 is located in alignment with the combustion chamber 21 and substantially on its longitudinal axis. Although this coaxial symmetry has several advantages, the invention is not limited thereto. In other embodiments of the apparatus for carrying out the combustion method of the invention, the pintle valve 25 is spaced from said longitudinal axis and/or at substantially any angle relative to the longitudinal axis of the inlet tube 29 and chamber 21. To position.

In various applications of the invention, the bell-shaped fuel distribution envelope 41 (Fig.
It is desirable that the pulverized fuel be deformed by the injected pulverized fuel into a fan-shaped pattern with a limited angle. 15 and 16 illustrate a modified pintle valve used to create a fuel distribution pattern that corresponds to a partial angular sector of the bell-shaped envelope 41. This modified pintle valve 225 has a fuel inlet tube 229 that is substantially similar to the inlet tube 29 of the valve shown in FIG. At the inlet end 230, the flow of carbonaceous fuel mixed with carrier gas enters the pintle valve 225 through the gap between the tube 229 and the centrally aligned pintle 227. At the right-hand end shown in FIG. 15, the pintle has a large-diameter circular end 231 with a tapered surface 232;
32 forms a seal against the valve seat 233 when the pintle 227 moves vertically to the left. In this embodiment, the pintle valve 225 differs from the valve 25 described above in that the circular end 231 has a thin-walled cylindrical skirt 234 integrally formed therewith, which skirt is located at the inlet end of the tube 229. It extends toward the inner wall of this inlet tube. As shown at 235, the skirt 234 is truncated proximate the end 231 to provide an opening 236 extending along the circumference of the skirt 234 over an angle corresponding to the angular range of the desired fan-shaped fuel distribution pattern. is forming. In one example, aperture 236 extends over an included angle of about 60 degrees. In this device, the pintle shaft 227 is slidably supported for movement in the longitudinal direction of the inlet tube 229 without rotation. When the pintle shaft 227 is moved to its closed position (as shown in Figure 15), the tapered portion 232
The rim forms a seal against the valve seat 233, reducing the flow rate of fuel and carrier gas to approximately zero. When the pintle is moved to its fully open position shown in FIG. 16, the skirt 234 maintains a sliding seal against the inner wall of the inlet tube 229 and prevents the escape of fuel and carrier gas other than in the area of the opening 236.
Thus, as shown in FIG. 16, the pressurized flow of fuel and carrier gas flowing through inlet tube 229 exits through aperture 236 and is restricted to a portion corresponding to the angular portion of bell-shaped envelope 41 of FIG. ejects into the combustion zone in a fan-shaped pattern at a fixed angle. When the pintle 227 is moved from the open position shown in FIG. 16 to the closed position shown in FIG. decreases to In this device, the sector-shaped pintle valve has an aperture 236 extending along its periphery, although other equivalent structures may be used, such as a plurality of angularly spaced cylindrical holes.

Other examples of reaction chamber structures shown in FIGS. 17, 18, and 19 have advantages for high pressure applications. As shown in FIG. 17, the chamber 240 has a double wall structure having an outer wall 242 and an inner wall 243. inner wall 24
3 has coolant passages 244 chemically cut into its outer surface, as shown in FIG. The coolant passages extend through the outer wall 242 through the rib portions 24 between the passages 244.
It is closed by seam welding at 6. The heat exchange mechanism receives coolant at an inlet 248 of a water manifold 249 and transfers the coolant to a passageway 248.
44 and exhausts the coolant through outlet manifold 250. A layer of slag covering the interior metal walls 243 of the chamber reduces heat transfer to the coolant and minimizes enthalpy losses from the flow of gaseous combustion products.

For a given combustion temperature determined by regulation of the relative feed ratios of fuel and oxidizer, the slag produced during combustion will form a coating of solidified slag covering the metal inner surface 243 of the chamber 240 up to a certain thickness. An insulating layer of solidified slag accumulates and subsequently deposited slag is substantially insulated from the cooling effects of water in heat exchange passages 244 . At this point, equilibrium between the solid and liquid slag is reached and a fluidized layer of liquid slag covers the insulating layer of solidified slag. This layer of liquid slag flows by gravity toward the bottom of the combustion chamber where it is rejected into a liquid slag trap 252. In FIG. 17, opening 254 is a tangential oxidant inlet corresponding to inlet 59 in FIGS. 7 and 8. In FIG.

Next, a method for producing generator gas or synthesis gas will be described for reference. It should be noted that the following explanation does not constitute the gist of the method of combustion of carbonaceous fine powder solid fuel of the present invention.

The illustrated apparatus 10 can be used to produce generator gas in air under conditions favorable to the formation of carbon monoxide. The generator gas from the system 10 is sent to a conventional gas or oil fired burner to provide fuel for the burner. That is, this device provides a means for burning coal to produce a gaseous fuel that can be used as a replacement for natural gas or oil.

The system shown in FIG. 21 schematically illustrates the process for producing generator gas using the apparatus 10.
The oil combustor device 10 is of the type described above;
In this device, the fuel particles are combusted before impacting the internal walls of the device. Preferably preheated compressed air is passed through a valved line 300 to the device 1.
0 reaction chamber in the above-mentioned spiral state. Pulverized coal is injected through a pintle (not shown).
Carbonate is added to the reaction zone to remove SO _x from the reaction products. By controlling the flow rate ratio of coal to air, the amount of carbon monoxide is minimized. The combustible gas is sent as exhaust gas, optionally through a gas filter, to a gas- or oil-fired burner.
Slag particles that come out with the exhaust gas are captured by a filter and removed as waste. The slag is withdrawn from the apparatus 10 and disposed of at a suitable treatment facility.

When producing synthesis gas, oxygen is used in place of air and water vapor is injected into the reaction zone of apparatus 10.
Therefore, there is almost no nitrogen in the exhaust gas coming out of the device 10. In this case, line 300
The valve 310 in the oxygen source 322 is closed and the valve 320 is opened, which controls the flow of oxygen from the oxygen source 322. The flow rates of coal, oxygen, and steam are controlled so that the desired amounts of carbon monoxide and hydrogen are produced within apparatus 10. This synthesis gas is then passed through a hot gas filter and sent to a chemical plant where the synthesis gas is used to produce chemicals. When making synthesis gas, it is desirable to add carbonate to remove SO _x from the exhaust gas.

Next, coal pyrolysis, shale retorting, and flame cracking will be explained.

Apparatus 10 can also be used to process coal, shale, or petroleum. As shown in FIG. 20, the system for this has at least three stages. The first stage of the system is device 10. The second stage is an afterburner that completely burns out the reaction products exiting the device 10.
Preheated air or oxygen is injected into the second stage to minimize the temperature of the exhaust gas exiting this second stage. The third stage is a reaction chamber into which shale, coal or oil is injected. Hot gas from apparatus 10 is injected into the third stage of the shale,
Contact with coal or oil. In the case of coal, the water is removed to dehydrate the coal and evaporate the hydrocarbons.
The remaining char is then easier to transport.
In the case of shale, the carbonaceous material of the shale is decomposed into oil, which is then vaporized and removed from the third stage. If oil is the third
When injected into the stage, this oil is flash cracked into light hydrocarbons.

As previously mentioned, the pulverized coal injected into the combustor device 10 is mixed with carbonate to reduce SO _x production. Remove and process slag. The exhaust gas from the third stage is cooled by quenching, and the volatiles coming out of the third stage are collected with the exhaust gas and stored as a chemical feed.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view of an apparatus for carrying out the method of combustion of carbonaceous powder solid fuel of the present invention, and FIGS. 2a to 2d are perspective views showing a spiral swirling flow created in the apparatus of FIG. 1. 3 to 6 are graphs illustrating various types of high velocity fluid flows and the movement of particles in a rotating fluid environment; FIG. 7 is a partially cut away perspective view of an apparatus for carrying out the combustion method of the present invention; Figure 8 is the 7th
9 to 12 are side views showing a partial cross section of the device shown in the figure, lines 9-9 and 10 of FIG. 8, respectively.
-10, 11-11 and 12-12; FIG. 13 is a schematic diagram of the dense phase reactant transport device of the present invention; FIG. 14 is a partial cross-section of a portion of the device of FIG. 15 and 16 are side views showing partial cross sections of other embodiments of the apparatus shown in FIGS. 7 and 8, and FIG. 17 is a side view showing the combustion method of the present invention. A vertical cross-sectional view showing another structure of the reaction chamber of the apparatus, FIG. 18 is the same as 18-18 in FIG.
19 is a cross-sectional view showing a part of the structure shown in FIG. 17 in detail, and FIG. 20 is a cross-sectional view taken along the line, and FIG. 20 is a cross-sectional view showing a part of the structure shown in FIG. A flow diagram showing, for reference, the method of making the combustion method, and FIG. 21 shows, for reference, a method of performing coal pyrolysis, shale retorting, or petroleum flame cracking using the apparatus for carrying out the combustion method of the present invention. This is a flow diagram. 21,240... combustion chamber, 22... combustion zone,
23,230...Inlet port, 24,254...Inlet port, 25,225...Pintle valve, 35...Bassful, 37...Center opening.

Claims (1)

[Claims] 1. A combustion method in which an oxidizing gas and a granular solid carbonaceous fuel are introduced into a combustion chamber, and the input ratio and combustion temperature are adjusted to minimize the concentration of volatilized slag in the gaseous combustion products. (a) maintaining the walls of the combustion chamber within a temperature range such as to maintain a layer of liquid slag on the inner surface of the walls of the combustion chamber; and (b) discharging an oxidizing gas within an annular portion of the combustion zone adjacent said inner surface. and (c) introducing an oxidizing gas into said combustion zone within the combustion chamber so as to create a high-velocity rotating flow of combustion products; introducing a carbonaceous fuel into the combustion zone; (d) independently adjusting the velocity of the solid fuel and the velocity of the oxidizing gas and their relative flow rates, such that: (a) the residence time is on the order of several hundred milliseconds; (a) creating a combustion temperature higher than the temperature at which at least 90 percent of the non-combustible substances in the fuel are melted and lower than the temperature at which they vaporize; and (c) oxidizing. A fuel-rich state is created in which the stoichiometric amount of the agent gas is 0.4 to 0.9; (e) Most of the non-combustibles in the fuel are dissolved and deposited as a liquid slag that is removed in liquid form from the combustion chamber, thereby removing gaseous combustion products from the combustion chamber. A process characterized by separating the slag from the gaseous combustion products before exiting. 2. Particulate solid carbonaceous fuel is introduced into the combustion chamber in a diverging conical distribution pattern, and the angular velocity difference between the fuel particles and the oxidizing gas is such that the angular velocity difference between the fuel particles and the oxidizing gas increases while the fuel is flying within the combustion chamber. 2. The combustion method of claim 1, wherein the angular velocity difference is sufficient to promote rapid and stable combustion of substantially all of the carbon content. 3. The combustion method according to claim 1, further comprising the step of introducing a predetermined chemical reactant into the combustion chamber. 4. The combustion method of claim 1, further comprising the step of introducing into the combustion chamber an entrained stream of finely divided solid chemical reactants carried in a fluid carrier medium. 5. injecting particulate solid carbonaceous fuel in a diverging and substantially conical distribution pattern oriented substantially coaxially with said combustion zone, directing at least a majority of said oxidant gas to said combustion zone; by injecting the oxidizer gas substantially tangentially and adjusting the input rate of the oxidant gas such that substantially all slag liquid particles having a diameter of about 10 microns or more are hydrodynamically ballistically distributed around the combustion zone as a liquid. 2. A combustion method as claimed in claim 1, characterized in that the gaseous combustion products are deposited and thereby separated from the gaseous fuel products and that such gaseous combustion products are subsequently conditioned to exit the combustion zone. 6. The combustion zone has radial and longitudinal directions such that substantially all of the slag liquid particles are hydrodynamically ballistically directed towards the walls of the combustion reaction chamber and deposited as liquid on these walls under centrifugal action. A combustion method according to claim 1, characterized in that the combustion reaction chamber is in a substantially cylindrical combustion reaction chamber having dimensions and shape. 7. The granular solid carbonaceous fuel consists of pulverized coal,
2. A combustion method as claimed in claim 1, characterized in that substantially all of the carbon content of the coal particles is converted to carbon oxides while the fuel is in flight within the combustion chamber. 8 Injecting carbonate and mixing it with the rotating flow in the combustion chamber, causing a significant portion of the sulfur compounds in the coal to react with the carbonate and centrifugally depositing on the walls of the combustion chamber. 8. A combustion method as claimed in claim 7, characterized in that it produces a slag-like material which is removed from the combustion products exiting the combustion chamber. 9. The process of pulverizing coal into powder, the coal particles being distributed in the combustion chamber in a conical distribution pattern, and the angular velocity difference between the coal particles and the oxidizing gas causing the coal to fly. introducing the oxidizer gas at an angular velocity substantially lower than that of the oxidizer gas so as to promote rapid combustion of the carbon content of the coal particles with a flight time of several hundred milliseconds or less. The combustion method according to claim 1. 10 the fuel particles with the carrier fluid, 1:
characterized by entraining a fuel to carrier fluid mass ratio in the range of 1 to 100:1, thereby providing adjustment of the fuel to oxidizer gas ratio without the use of moving parts in the hot portions of the combustion chamber. The combustion method according to claim 1. 11 The high speed rotational flow converts most of the fuel particles into carbon oxides, substantially converting the carbon content of the fuel particles into carbon oxides before the fuel particles hit the inner surface of the combustion chamber or before they exit the combustion chamber. 2. Combustion method according to claim 1, characterized in that it is suspended in the swirling gas for a flight combustion time sufficient for complete conversion. 12. positioning an annular slug buttful adjacent the downstream end of the combustion chamber to force the rotational flow into a small diameter channel thereby increasing the centrifugal force exerted on the liquid slug droplets; Flow-entrained powdered carbonaceous fuel particles of about 75 microns or less in diameter, the fuel particles having an entrained mass ratio of fuel particles to carrier fluid in a range of about 2:1 to about 10:1. Combustion method according to claim 1, characterized in that it is introduced into the combustion zone. 13. Introducing the solid carbonaceous fuel into the combustion zone at a speed sufficiently lower than the flow rate of the oxidizing gas to maintain a fuel-rich state within a central portion extending in the length direction of the combustion zone, and an oxidant gas in the annular portion of
A combustion method according to claim 1, characterized in that the flow rate of the fuel and fuel products is so great that substantially all the gaseous fuel products leave the combustion zone within a residence time of several hundred milliseconds. . 14. The claim further characterized in that the flow velocity within the combustion zone is maintained at a velocity sufficient to cause substantially all of the gaseous combustion products to pass through the combustion zone within a residence time of about 100 milliseconds. The combustion method according to scope 13. 15. Combustion according to claim 1, characterized in that an oxidizing gas is introduced into a second combustion zone downstream of the first combustion zone to further oxidize the combustion products exiting the first combustion zone. Method. 16. The combustion method of claim 1 further comprising introducing an additional predetermined chemical reactant into the combustion chamber. 17 The fuel has a fuel to carrier mass ratio of 1:1.
Combustion method according to claim 1, characterized in that it is entrained in the carrier in the range ˜100:1. 18. Combustion method according to claim 16, characterized in that carbonaceous material is introduced into the rotating flow. 19 The gaseous combustion products from the first combustion zone are
16. The combustion method of claim 15, wherein the combustion process flows through an apertured baffle to the downstream reaction zone, the apertured baffle separating the liquid slag from the gaseous combustion products.